Thermal fuse.



C. F. PECKHAM.

THERMAL FUSE.

APPLlCATlON FILED MAY 11, 1911- 1,259,662, Patented Mar.19,1918.

CHARLES E. rEoKnAn, or rnovrnnlvon, iaHonE ISLAND.

THERMAL Fuss.

Application filed May'17, 1917.

To all whom it may concern:

Be it known that I, CHARLns F. PECK- HAM, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode lsland, have invented certain new and useful Improvements in Thermal Fuses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap pertains to make and use the same.

The invention relates to a thermal or heat-actuatedfuse which is particularly designed and adapted for use in automatic sn'i'nkler heads, but which is capable of use in other devices and mechanisms Where analogous conditions obtain.

The primary object of the invention is to provide a novel and improved fuse which is well adapted for use inthe well-known forms of sprinkler heads now in general use, and which, when so used, will eliminate the object-ions incident to' uniting the parts of a collapsible valve-holding strut by fusi ble solder.

Other objects of the invention are to provide a fuse of a form to exposethe maximum surface for the absorption of heat, to prevent the transmission of heat or electric currents between the fuse and the parts of the deviceto which it is applied, and to protect the fuse from the action of corrosive chemicals or fumes.

To these ends the" invention consists in the features of construction and combinations of parts hereinafter described and referred to in the claims.

T he various features of the invention will be readily understood from an inspection of the accompanying drawings and the following detailed description of the construction referred to therein. I

In" the drawings, Figure 1 is a side elevation partly in section, of one form of automatic sprinkler head equipped with a thermal fuse embodying a preferred form of the invention; Fig. 2 is a vertical sectional view of another form of automatic sprinkler head equipped with the fuse; and Fig. 3 is an enlarged sectional view through the axis of the fuse.

The fuse is formed of a metal, such as solder, which has a comparatively low fusing point, and which is commonly referred to in the sprinkler art as a fusible metal. As shown in Fig. 3 of the drawings, the

Specification of Letters Patent.

Patented Mar. 19, 1918.

Serial No. 169,238.

fuse comprises a hollow cylinder 1 having a head 2 at its outer end adapted to support the end 3 of a red at which engages the head of the cylinder. As here shown, the rod is in the nature of a lie-rod passing through the cylinder and having a headed end which abuts against the head of the cylinder. The cylinder is preferably in the form of a thin shell, and the head is preferably frusto conical in' shape, since this structure presents a comparatively large heat-absorbing surface, and will quickly fuse and release the rod when subjected to heat, and at the same time has the requisite strength to effectively support a comparativ' ely heavy pressure. As shown, the head of the fuse recessed to receive the head of the tie-rod, and it is preferred to separate the rod and fuse by a gasket 5 ofinsulating material which is a non-conductor of heat as well as electricity. The inner end of the fuse is supported upon a supportin member 6, from which it is preferably insulated by an interposed gasket 7 of insulating material. gaskets serve to protect the fuse frbm' electric currents and electrolytic action which might otherwise destroy or impair its efficiency. They also prevent the transmission of heat between the fuse and the parts with which it is connected, so that the fuse is unaffected by the temperature of these parts. which might otherwise tend to re 'ard the melting of the fuse.- The fuse may be protected from the action of corrosive elements by covering it with a casing of noncorrosive heat-conducting material indicated at 8. This casing may be in the form of a foil or plating, or may be thin shell inclosing the fuse.

In the constructioir shown; the inner end of the tie-rod l carries a nut- 9 which engages a member 1 0 andholds' it against movement with relation to the supporting member 6 so long as the fuse remains intact.

-When the fuse is subjected to" a temperature" high enough to fuse it, the rod l is no longer supported against endwise movement, and the member 9 is free to move with relation to the member 6.

In applying the fuse to a sprinkler head having the form of collapsible strut inclicated in Fig. 1, the inner end of the fuse may be connected with or supported on the member 11 of the strut, while the tie-rod binds the member .12 to the member 11 so that these members form a rigid strut between the members 13 and 14 so long as the fuse remains intact. When the sprinkler head is subjected to heat, however, the fuse quickly melts and collapses, so that the members 11 and 12 are free to move with relation to each other, thus allowing the entire valve-holding strut to collapse and fly apart.

In applying the fuse to a sprinkler head having the construction shown in Fig. 2, the fuse may be secured to or supported by the locking plate 15 while the tie-bolt binds this plate to the post 16 so long as the fuse remains intact. When the fuse melts, the locking plate 15 is released, so that the post and plate may move relatively to each other, thus allowing the valve-holding strut to collapse and fly apart.

While it is preferred to employ the specific construction of fuse shown and described, it will be understood that this construction may be varied or modified without departing from the broader scope of the invention. It will also be understood that in applying the fuse to a sprinkler head the arrangement of the fuse, and the manner in which the rod is connected to the collapsible strut to prevent its collapse until the fuse melts may be varied or modified as found desirable or best suited to the construction and arrangement of the parts with which the fuse and rod are combined.

Having explained the nature and object of.the invention, and specifically described one structure inwhich it may be embodied,

what is claimed is 1. A thermal fuse comprising a' fusible hollow cylinder one end of which isprovided with a pressure supporting head for supporting a rod engaging the head, and said rod.

2. A thermal fuse comprising a comparatively thin fusibe shell the outer end of which is provided with a head recessed to support the head of a tie-rod passing through the shell, and said rod. 7

3. A thermal fuse comprising a comparatively thin fusible shell the outer end of which is provided with a frusto-conical head recessed to support the head of a tierod passing through the shell.

4. A thermal fuse comprising a fusible hollow cylinder one end of which is provided with a pressure supporting; head for supporting the end of a rod engaging said head, and said rod.

5. A thermal fuse comprising a fusible cylinder, a supporting member for oneend of the cylinder, a rod passing through the supporting member and provided at one end her held by the other end of the tie-rod from movement relatively to the supporting member.

7. A thermal fuse comprising a fusible cylinder, a supporting member for one end of the cylinder, an insulating gasket be tween theend of the cylinder and the support, a rod passing through the supporting member and provided at one end with a head supported by the cylinder, an insulating gasket between the head of the rod and the cylinder, and a member held by the other end of the tie-rod from movement relatively to the supporting member. 7

8. A thermal fuse for preventing the collapse of the valve-holding strut of a sprinkler head comprising a fusible cylinder, and a rod connected to resist the collapse .of the strut and having one end supported by the cylinder.

9. A thermal fuse for preventing the collapseof the valve-holding strut of a sprinkler head comprising a fusible cylinder, one 'end of which is supported on one member of the strut, and a tie-rod connected to another member of the strut and having a head supported by the cylinder. 7

'10. A thermalfuse comprising a comparatively thin fusible shell one end of which is provided with a headfor supporting the end of a rod engaged therewith, and said rod.

f CHARLES PECKHAM.

Copies 01 this patent may be ettained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G

It is hereby certified that in Letters Potent No. 1,259,662, granted March 19, 1918, upon the application of Charles F. Peckham, of Providence, Rhode Island, for an improvement in Thermal Fuses, an error appears in the printed specification requiring correction as follows: Page 2, lines 72 and 84, claims 6 and 7, strike out the word and hyphen tie-; and that the said Letters Patent should be read with this correction therein that the some may conform to the record of the case in the Patent Oflice. I

Signed and sealed this 23d day of April, A. D., 1918.

[SEAL] F. W. H. CLAY,

Acting Commissioner of Patents. 

